Boat construction



Oct. 19, 1943. J. w. SMITH 2,

BOAT CONSTRUCTION Filed Sept. 21, 1940 2 Sheets-Sheet 1 c A INVENTOR.

JAY W.SMITH m ATTORNEYS Oct. 19, 1943. J. w. SMITH 2,332,178

BOAT CONSTRUCTION Filed Sept. 21, 1940 2 Sheets-Sheet 2 INVENTOR.

JAY W. SMITH A TTORNEYs Patented Get. 19, 1943 BOAT CONSTRUCTION Jay W. Smith, Algonac, Mich., assignor to Chris Craft Corporation, Algonae, Mich., a corporation of Delaware Application September 21, 1940, Serial No. 357,813

3 Claims.

This invention relates generally to power boats and refers more particularlyto boats of the type adapted to be grounded for landing purposes.

Qne of the principal objects of this invention resides in the provision of means for exerting an upward thrust on the hull of the boat to elevate the latter at the time the propeller is operated to move the boat in one direction.

Another object of this invention resides in the provision of a booster plate hinged at its rear edge to the bottom of the boat in advance of the propeller in a manner to permit the front edge of the plate to swing downwardly from a position against the bottom of the boat to a position in the slip stream of the propeller. As a result, the booster plate cooperates with the slip stream of the propeller when the latter is rotated in the reverse direction to impart an upward thrust on the boat tending to elevate the latter and thereby assist the propeller in moving the boat off the ground.

A further object of this invention resides in the provision'of a construction of the type previously set forth wherein a certain amount of water in the siip stream of the propeller is passed beneath the free edge of the booster plate to impart a propelling force to the boat at the same time the elevating eifort is exerted on the boat. It follows from the above that the proportion of the propelling force embodied to elevate the boat is dependent upon the angular position of the booster plate with respect to the slip stream of the boat to operate the booster plate and adjust the angular position of the latter relative to the slip stream of the propeller to obtain the required proportion of propelling and elevating force.

The foregoing as well as other objects will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure l is a side elevation view of a boat equipped with a booster plate forming the subjcct matter of this invention;

Figure 2 is a fragmentary plane view of the construction shown in Figure 1 having certain parts broken away for the sake of clearness;

Figure 3 is an enlarged sectional view taken substantially on the plane indicated by the line 33 of Figure 2 Figure 4 is a fragmentary perspective view illustrating the control mechanism.

For the purpose of illustrating the present invention, I have selected a power boat of thepower boat embodying a propeller for creating a slip stream beneath the hull of the boat.

In Figure 1 of the drawings, I have shown a power boat having a hull l0 and having dual pf'opellers ll supported beneath the hull adjacent the stern of the latter. In accordance with the conventional practice, the propellers H are positioned adjacent opposite sides of the hull and each propeller is connected to a suitable prime mover (not shown) within the hull by means of a drive shaft l2. Each drive shaft i2 is rotatably supported adjacent the propeller by means of a bearing [3 carried by a bracket M which, in turn, is secured to the bottom of the hull it.

In the present instance, each bracket M has a depending extension I5 secured to the rear end of a skid l6 having the forward end fixed to the bottom of the hull. The arrangement is such that the skids l6 protect the propellers H and associated drive shafts l2 from contact with submerged obstructions upon forward motion of the boat. The propellers and associated parts are also protected from submerged obstructions when the boat is moved in a reverse direction by a pair of rudder guards I! having the forward ends respectively secured to the rear ends of the skids I6 and having the rear ends secured to the bottom of the hull rearwardly of the prop ller. As is usually the case, a pair of rudders l8 are respectively positioned beneath the hull in rear of the propellers within the space defined by the guards l1. These rudders are suitably operatively connected to a control wheel l9 mounted in the hull at the control station for simultaneously turning the boat rudders to eifect proper steering of the boat.

In Figure 1 of the drawings, the arrow identified by the reference character A indicates the slip stream of one of the propellers when the lat ter is rotated in a direction to impart a forward motion to the boat, and the arrow B indicates the slip stream when the propeller is rotated in a reverse direction to impart a rearward motion to the boat. The cooperating propeller acts in an identical manner when rotated in unison with the propeller aforesaid.

In accordance with the present invention, means are provided for cooperating with the slip streams B of the propeller to impart an elevating force on the bottom of the hull at the same time the propellers are applying an effort against the hull attempting to move the same in a rearward direction. This arrangement is particularly advantageous in cases where the bow portion of the boat is grounded because it enables the boat to be moved off the ground orobstruction under its own power.

The above results are obtained by mounting a pair of booster plates and 2| on the bottom of the hull in advance of the propellers. Upon reference to Figure 3, it will be noted that" the rear edges of the plates are pivotally mounted on the bottom of the hull by means of hinge members 22 which permit the plates to be swun from an inoperative position against the bottom surface of the hull to an operative position illustrated by the dotted lines in Figure 3. the booster plates 29 and 2| are in their inoperative positions against the bottom surface of the hull, the forward or swinging edges of the latter are protected by strips 23 secured to the bottom of the hull immediately in front of the swinging edges of the booster plates and have a length approximating the length of the booster plates. The thickness of the rear-edge of the strips is substantially equal to the thickness of the booster plates, and the bottom surfaces of the strips are curved upwardly from the rear edges of the strips to the forward edges of the latter. As a result, the water will, in effect, slip past the guard strips 33 with the minimum resistance and will be prevented from impinging against the free swinging edges of the booster plates.

It will be observed from the above that when the booster plates are swung downwardly relative to the bottom of the hull, they project into the slip streams B of the propellers and a certain amount of the force of the slip stream is applied to the booster plates tending to lift or elevate the stern of the hull. The proportion of the force of the slip streams applied to the booster plates is dependent upon the angular position of the booster plates with reference to the slip streams, and provision is made herein for locating the booster plates at different angles relative to the slip streams to vary the amount of elevating effort applied to the hull. Regardless of the angular positions of the booster plates relative to the hull, a sufiicient amount of the slip streams escape underneath the swinging edges of the booster plates to apply a substantial propelling effort on the hull in a rearward direction.

Referring now to the means for operating and adjusting the booster plates, it will be noted from Figure 3 of the drawings that the swin ing edge portion of the booster plate 20 is connected adjacent opposite ends thereof to a shaft 24 by a suitable linkage 25. The shaft 24 is mounted within the hull adjacent the rear bulkhead 26 for rocking movement, and the linkage extends through the bottom of the hull forpivotal connection with the plate 20.

Upon reference to Figure 2, it will be noted that the opposite ends of the shaft 24 are journaled in suitable bearings 21 forming a part of the brackets 28 which, in turn, are secured to the bulkhead 23. A pair of arms 29 have the When rear ends thereof keyed or otherwise suitably secured to the shaft 24 at points spaced longitu dinally of the latter and have the forward ends respectively pivotally connected to a pair of clevises 30 by means of pins 3| extending through elongated slots 32 in the forward ends of the arms 29. As shown in Figure 3, each clevis 30 is adjustably secured to the upper end of a rod 33 having the lower end slidably engaging a coupling 34. The coupling 34 is formed with an attaching flange 35 which is secured to a filler block 35, and the lower end of each coupling extends into a recess 31 formed in the bottom of the hull directly above the booster plate 29. The lower end of each rod 33 projects beyond the associated coupling 34 into the registering recess 31 and is pivotally connected to the booster plate 29. In detail a fixture or bracket 33 is suitably secured to the swinging edge portion of the booster plate 29 adjacent opposite ends of the latter, and the lower ends of the rods 33, respectively, extend through openings formed in the brackets. A pivot pin 39 extends transversely through each bracket 38 and projects through an elongated slot 49 formed in the adjacent end of the associated rod 33. The elongated slots 32 and 40 permit the required arcu'ate travel of the arms 29 and booster plate 29 without binding the reciprocable rods 33 in the couplings 34.

It may be pointed out at this time that the lower end of each rod 33 is provided with a head 49' above the pivot pin 39 for abutting engagement with the adjacent end of the associated bracket 38. The arrangement is such that the elevating thrust applied to the booster plate 20 is taken directly by the rods 33 without passing through the pins 39. As a result, the pins 39 are relieved of any stress applied to the booster plate 2!] in an upward direction.

In order to prevent leakage through th couplings 34, provision is made herein for sealing the space around the rods 33. Upon reference to Figure 3, it will be noted that each of the couplings 34 are provided with an upwardly extending threaded hub 4| and a suitable seal 42 is secured to the threaded hub around the associated rod 33. The seals 42 are in the form of an adjustable packing capable of effectin the desired seal without interfering with reciprocation of the rods 33 relative to the couplings 34.

The shaft 24 is rocked to operate the booster plate 29 from a position adjacent the control wheel I9 by means of a manually operable lever 43 pivotally mounted intermediate the ends on a transverse shaft 44. The shaft 44 is suitably supported on a bracket 44' and the lower end of the lever 43 is pivotally connected to the upper end of a link 49 having the lower end thereof pivotally connected to an arm 41 of a bell crank lever 48. The bell crank lever 48 is mounted on a rock shaft 49 suitably supported adjacent the bottom of the hull l0, and the other arm 59 of the bell crank lever is operatively connected to the rock shaft 24 by means of a rearwardly extending link 5!. In th present instance, the rear end of the link 5| is pivoted to a lever 52 which is secured to the rock shaft 24.

Upon reference to Figure 1, it will be noted that when the booster plate 29 is in its inoperative position against the bottom surface of the hull I 9, the link 46 and lever 43 on the rock shaft 44 are insubstantial alignment with each other. As a result, the booster plate 20 is locked in its inoperative position by the linkage and is prestream of the propeller, the operator merely swings the control 43 in the direction of the arrow C. Movement of the control 43 in the above direction effects the required rocking movement of theshaft 24 to swing the booster plate 20 into the slip stream of the propeller. It may be pointed out at this time that the booster plate 20 is held in any one of the adjusted positions relative to the slip stream of the propeller by means of a quadrant 53secured in a position ad-' jacent the control arm 43 and having a plurality of notches 54 therein for successively engaging a suitable spring pressed detent 55 carried by the control arm 43. r

In the present instance, the booster plate 2i is operated as a unit with the booster plate 20 from the control arm 43. For accomplishing this result, a shaft 56 is supported for rocking movement on the bulk head 26 of the hull in alignment with the shaft 24 and is connected at opposite ends with the swinging edge of the booster plate 2| by the linkage 51. This linkage is identical in construction to the linkage 25 previously described in connection with the booster plate 23. The rock shaft 26 is connected to the rock shaft 49 by means of a link 58 so that manipula-.

tion of the control arm 43 to eifect a rocking movement on the shaft-49 causes a rocking movement of the shaft 56 as Well as the shaft 24. Ac-

cordingly, both booster plates will be moved into or out of their respective slip streams depend-. ing upon the direction of swinging movement of the control arm 43.

What I claim as my invention:

1. A boat'having a propeller rotatable to provide a slip stream beneath the boat, a plate positioned against the bottom surface of the boat directly above the slip stream and forwardly of the propeller, and means hingedly mounting the.

plate on the boat to permit swinging the plate into the slip stream of the propeller at an angle to the slip stream and thereby diverta portion of the propelling force of the slip stream in an upward direction toward the bottom of the boat.

2. A boat having a hull and having a propeller rotatably-supported on the hull, a plate positioned against the bottom surface of the hull directly above the slip stream forwardly, of the propeller and having opposite edge'portionsextending transversely of the boat, means hingedly mounting one of the edge portions of the plate on the hull to permit swinging the other of said edge portions into the slip stream of the propeller and thereby divert a portion of the propelling force of the slip stream in an upward direction against the bottom of the hull, and means accessible for manipulation within the boat for swing 25 mg said plate.

3. A boat having a hull and having a pair of propellers mounted on the hullbeneath the latter at opposite sides of the longitudinal'center line ofthe hull to provide laterally spaced slip streams beneath the hull, a pair of plates respectively I streams of the propellers, and means accessible from a position. within the boat for operating said plates.

JAY W. SMITH, 

